The present invention relates to can crushers, and especially to a can crusher of the type that alternately crushes one can at a time being fed thereto.
In the past, a great variety of machines have been provided to shred cans or to compact cans to reduce the space the cans take up in storage and shipping for recycling. This becomes more important as the price of aluminum and the cost of energy rises, since a considerable portion of the price of producing raw aluminum from ore is in the large amount of electrical energy required. Many of the prior art machines developed for compacting cans have been too bulky or expensive for placement at retail outlets where the crushed cans can be easily stored and eventually picked up for recycling. Many prior art can crushing mechanisms crush the cans in a random fashion, so that the cans retain small amounts of liquid therein. If the aluminum cans are fed directly to melting furnaces in this manner, the liquid tends to expand and cause the cans to explode. Accordingly, it has been common for large volumes of cans to be shredded into fine pieces, but this takes large, expensive machinery, and tends to generate large amounts of fine aluminum dust and particles.
The present invention, on the other hand, is directed toward an inexpensive but fast can crusher which compacts the can in a manner to force any liquid from the can, and which can be used at retail outlets or at central collection points for rapid processing of large volumes of cans.
One prior art U.S. Pat. No. 3,659,520 to Garritt, et al., teaches a beverage can compressor operating with a sliding ram driven by an eccentric mounted disc driving a cam follower which is spring returned. Cans in this mechanism are compressed from the side. The cans are allowed to roll into the compacting areas with each can stopping the previous can. A spring supports the can in position and is pushed out of the way during the compacting operation. The ram is driven by an electric motor through considerable reduction gearing. Another patent operating in a similar manner to the present invention is the Bishoff U.S. Pat. No. 3,817,169 for a can crusher driven by an electric motor driven eccentric which slides a ram for crushing a can between the can ends. This can crusher includes a can feeding chute for feeding the cans one at a time into a cylindrical crushing area, and requires a mechanism for lifting each can on the chute up into the semi-cylindrical area, thus, preventing the cans from interfering with each other during the compacting operation. In contrast to these prior two patents, the present invention is directed toward a more rapid crushing of cans utilizing a single cam drive shaped to drive a pair of rams, each ram connected to each other with a spring return, and each sliding on a single pair of guides, which also have the anvils attached to the ends thereof.
Other typical prior U.S. patents dealing with can crushers may be seen in the Smith U.S. Pat. No. 2,619,150; and in the Heiser U.S. Pat. No. 3,916,780; and in the Gurtin U.S. Pat. No. 3,772,985.